In a few decades of reconstruction, even the mathematical natural sciences, the ancient archetypes of theoretical perfection, have changed habit completely!

Without troublesome work, no one can have any concrete, full idea of what pure mathematical research is like or of the profusion of insights that can be obtained from it.

If all consciousness is subject to essential laws in a manner similar to that in which spatial reality is subject to mathematical laws, then these essential laws will be of most fertile significance in investigating facts of the conscious life of human and brute animals.

Natural objects, for example, must be experienced before any theorizing about them can occur.

Science is a river with two sources, the practical source and the theoretical source.

Something similar is still true of the courses followed by manifold intuitions which together make up the unity of one continuous consciousness of one and the same object.